A series of strong upper waves dug east-southeast across northwest California resulting in periods of strong winds and mountain snow.
Every event with a place to put it; 51 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS EKA wrote it up.
A series of strong upper waves dug east-southeast across northwest California resulting in periods of strong winds and mountain snow.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Eureka, CA wrote its last area forecast discussion before the first event at Jan 24, 4:37 AM PST, 4 hours 53 minutes earlier.
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
437 AM PST Sun Jan 24 2021
.SYNOPSIS...A cold front will bring a period of rain, strong winds
and snow to the area today. Showers will linger into Monday.
Starting Tuesday afternoon a significant winter storm will bring
heavy rain, heavy low elevation snow, and strong winds through
Wednesday evening. Thursday and into the weekend additional rain
and snow is expected.
&&
.DISCUSSION...A strong and dynamic cold front is approaching NW
Ca this morning. Water vapor sat is showing strong drying behind
the front indicative of the sinking air bringing strong winds to
the surface. Hires models are showing a dramatic wind shift and
strong northwest winds immediately behind the front over the
waters and at the immediate coast. This is expected to move onto
the Humboldt and Mendocino coasts around midday and bring gusts of
45 to 50 mph behind the front so have issued a wind advisory to
highlight this. It is possible this could impact the Del Norte
coast or areas farther inland, but current models show lighter
winds in these areas so will hold off for now. Now that the models
are showing this system to be more dynamic, it is pulling in more
warm air with it. Snow levels in most areas will rise this
morning to 2,500 feet and have adjusted to the Winter Weather
Advisory to match. The exception will likely be northern Trinity
county where temperatures are currently below freezing and the
cold air will likely remain in place, but it still looks like it
will be hard to see much snow below 2,000 ft so adjusted that
advisory as well. Areas in eastern Humboldt may see some trapped
cold air as well, but with the stronger winds this isn't expected
to last very long.
There is expected to be a short break in the rain behind the front in
the late afternoon. Showers will start to increase in the evening
and persist overnight into Monday. Overnight the models are
showing steep lapse rates aloft and the 06Z NAM is now showing 500
J/KG of Cape over the waters and just onto the coast. This will
likely produce some small hail and it is possible some snow could
make it down to 1,000 feet early Monday morning. Thunderstorms are
possible on the Humboldt and Del Norte coast in a few of the
heavier showers. For now it doesn't look like the snow showers
will widespread enough to warrant Winter weather advisory
overnight, but it is possible. In general these showers are
expected to remain close to the coast with Trinity, Lake and
interior Mendocino remain mainly dry on Monday. Showers are
expected to finally come to an end Monday evening with most areas
staying dry Monday night and Tuesday morning.
Tuesday afternoon an upper level low starts to approach the
Pacific NW and the associated frontal boundary starts to move
onshore bringing moderate precip and strong winds. There is quite
a bit of ensemble support for some strong winds as this moves
onshore. A wind advisory or warning will likely be needed for the
coastal counties Tuesday late afternoon and evening if this
remains on track with gusts to 50 or 60 mph at least on the
ridges. This system continues to look very cold. Snow levels with
the first round of precip Tuesday afternoon through Wednesday
morning are expected to be around 1,500 to 2,000 feet in northern
Humboldt, Trinity and Del Norte counties. Farther south in
Southern Humboldt, Mendocino and Lake counties snow are expected
to quickly rise to 2,500 to 3,000 feet. Areas above the snow level
could see as much as two feet of snow Tuesday afternoon through
Wednesday afternoon. The most challenging part of the forecast is
the snow levels. Ensembles have been in very good agreement on
these large amounts for several days, but it would only take a
small shift for snow levels to rise 500 feet and impacts would be
much lower. Farther south in Lake and Mendocino counties rainfall
amounts of 2 to 3 inches with local amounts up to 4 inches are
expected. This could produce some small stream flooding. Mainstem
rivers are expected to rise rapidly, but they are starting so low
flooding is unlikely to be a problem. This rain doesn't look like
it will be convective and rain rates are not expected to be high
enough to cause debris flows on the burn scars.
Wednesday night and Thursday the upper level low starts to become
more of an open wave trough and the airmass will start to
moderate. In general this will raise snow levels. The ensembles
are all over the place on how much precip we will through the
period. In general Mendocino and lake counties will the heavier
rain with this system. Flooding is not expected at this point, but
there is another round of precip expected at some point. It looks
like this system will generally move out of the are on Friday
before another system moves in for the weekend. MKK
&&
.AVIATION...An approaching front should keep ceilings MVFR
through the morning, with rain slowly increasing in intensity
heading toward noon along the north coast. This front is expected
to pass overhead just before noon north of Cape Mendocino and just
after noon for Mendocino and Lake counties, bringing intermittent
moderate rainfall, impacted visibilities and lowered ceilings.
Gusty north winds quickly behind the front as convective
precipitation rolls in, with fluctuating categories and turbulent
conditions expected through much of the afternoon. Conditions
should improve late this evening as the system exits to the
southeast, however scattered showers are expected to continue
through much of the night. /TDJ
&&
.MARINE...Light southerly winds briefly develop north of Cape
Mendocino early this morning as a fast-moving front approaches the
coast. Latest high-resolution model guidance is indicating winds
quickly switching to strong, gusty northerly gales late this morning
behind the front, with sustained speeds of 25 to 35 kts and gusts of
45 to 50 kts possible. Meanwhile, a mix of short-period, locally
generated waves and a mid period NW swell ramp combined seas up to
16 to 20 ft by this evening, with the largest seas and strongest
winds expected in the southern outer waters.
After the initial burst of northerlies this afternoon and evening,
winds slowly weaken Monday before turning southerly and accelerating
as a stronger front approaches on Tuesday. Short-period southerly
seas from these winds and a decaying NW swell will likely keep seas
elevated through the first half of this week. After this front moves
onshore late Tuesday, winds should remain southerly but become
significantly lighter through the middle of this week. Another NW
swell is set to fill in late Wednesday, bringing seas back into the
16 to 18 ft range before conditions potentially calm down late this
week into the weekend. /TDJ
&&
.BEACH HAZARDS...A long period westerly swell arriving this morning
will have the potential to produce a minor, short-lived sneaker
threat on area beaches Sunday morning. The swell will build in at
around 2-4 ft at 20 seconds during a relative lull in winds and
short period seas, prior to the onset of steeper short period seas
to mitigate the threat. Beachgoers are advised to remain aware of
their surroundings. Never turn your back on the ocean. /CB
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory from 1 PM this afternoon to 10 PM PST this evening
for CAZ109.
Winter Weather Advisory from 8 AM this morning to 7 PM PST this
evening for CAZ102-104>108.
Wind Advisory from 1 PM this afternoon to 7 PM PST this evening
for CAZ103-104.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until noon PST today for PZZ470-475.
Gale Warning from noon today to midnight PST tonight for PZZ470.
Gale Warning from noon today to 9 AM PST Monday for PZZ455-475.
Gale Warning from noon today to 9 PM PST this evening for PZZ450.
&&
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.pngHazardous Weather Outlook...UPDATED National Weather Service Eureka CA 404 AM PST Sun Jan 24 2021 CAZ102-105-106-251215- Del Norte Interior-Northern Humboldt Interior- Southern Humboldt Interior- 404 AM PST Sun Jan 24 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 7 PM PST THIS EVENING... This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. A Winter Weather Advisory is currently in effect. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Rain, strong winds and heavy snow are possible Tuesday afternoon through Thursday. Snow levels of 2000 to 2500 feet are expected. This has the potential to cause significant travel impacts and utility outages. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ112-113-115-251215- Southwestern Mendocino Interior-Southeastern Mendocino Interior- Southern Lake County- 404 AM PST Sun Jan 24 2021 This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. No hazardous weather is expected through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Moderate to heavy rain and snow are possible Tuesday afternoon through Thursday. This may cause minor flooding of small streams and in areas of poor drainage. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ103-251215- Northern Humboldt Coast- 404 AM PST Sun Jan 24 2021 ...WIND ADVISORY IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM PST THIS EVENING... This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. A Wind Advisory is currently in effect. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Moderate to heavy rain and gusty winds are possible Tuesday afternoon through Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ104-251215- Southwestern Humboldt- 404 AM PST Sun Jan 24 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 7 PM PST THIS EVENING... ...WIND ADVISORY IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM PST THIS EVENING... This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. A Winter Weather Advisory is currently in effect. A Wind Advisory is currently in effect. No hazardous weather is expected through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Moderate to heavy rain, strong winds and snow are possible Tuesday afternoon through Thursday. Snow levels are expected to be around 2,000 to 2,500 feet. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ109-251215- Mendocino Coast- 404 AM PST Sun Jan 24 2021 ...WIND ADVISORY IN EFFECT FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS EVENING... This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. A Wind Advisory is currently in effect. No hazardous weather is expected through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Moderate to heavy rain and strong winds are possible Tuesday afternoon through Thursday. This may cause minor flooding of small streams and in areas of poor drainage. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ107-108-251215- Northern Trinity-Southern Trinity- 404 AM PST Sun Jan 24 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 7 PM PST THIS EVENING... This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. A Winter Weather Advisory is currently in effect. No hazardous weather is expected through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Rain and heavy low elevation snow are possible Tuesday afternoon through Thursday. This has the potential to cause significant travel impacts and utility outages. Snow levels are expected to be around 1,500 to 2,000 feet. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ110-111-114-251215- Northwestern Mendocino Interior-Northeastern Mendocino Interior- Northern Lake County- 404 AM PST Sun Jan 24 2021 This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. Sunday afternoon 1 to 2 inches of snow is possible above 2,500 feet. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Heavy rain and snow are possible Tuesday night through Thursday. This may cause travel impacts. Snow levels are are expected to be 2,000 to 2,500 feet. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. CAZ101-251215- Coastal Del Norte- 404 AM PST Sun Jan 24 2021 This hazardous weather outlook is for northwest California. .DAY ONE...Today and tonight. No hazardous weather is expected through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Moderate to heavy rain and strong winds are possible Tuesday afternoon through Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
39 heavy snow, 29 winter weather, 4 high wind, 1 strong wind. Local standard time, as filed.
Public reports 1.5 inches of snow in Kneeland. Elevation was 2700 feet. Duration of the snowfall was 9.5 hours.
Spotter report of 5.5 inches of snow at an elevation of 2450 feet.
Twelve inches of snow. Power fluctuations reported.
Snowfall total of 28 inches at an elevation of 3099 feet.
Spotter reports 2 inches of snow at an elevation of 2450 feet.
Ten inches of snow at an elevation of 2100 feet.
Spotter report of 16 inches of snow at an elevation of 3805 feet.
Estimated 18 inches of snow at an elevation of 2800 feet.
Snowfall total of 5 inches at an elevation of 2300 feet.
Snowfall total of 12 inches at an elevation of 4220 feet.
Snowfall total of 8.8 inches at an elevation of 2532 feet.
Snowfall total of 10 inches at an elevation of 2762 feet.
Snowfall total of 13.5 inches at an elevation of 2675 feet.
One inch of snow in Willow Creek. Elevation approximately 610 feet.
Snowfall total 5 inches at an elevation of 1500 feet.
One inch of snow at an elevation of 1500 feet.
Social media report of 2.5 inches of snow at an elevation of 2400 feet.
Two inches of snow. Elevation unknown.
Social media report of 2.4 inches of snow occurring over a 6 hour period at an elevation of 1670 feet.
Five inches of snow at an elevation of 2200 feet.
Public reports 6.5 inches of snow at an elevation of 1500 feet near Hoopa.
Report of at least 4 inches of snow. Highway 101 closed due to heavy snow and downed trees.
Social media report of 8 inches of snow at an elevation of 2049 feet.
Estimated 11 inches of snow at an elevation of 1600 feet.
An inch of snow at an elevation of 1250 feet.
Spotter report of 6 inches of snow at an elevation of 1950 feet.
Six inches of snow at an elevation of 2700 feet.
Highway 101 closed due to at least 4 inches of snow accumulation.
Four inches of snow.
Multiple vehicles stuck on Route 253 due to at least one inch of snow.
Snow accumulations of at least 2 inches led to 40-50 vehicles becoming stuck along Highway 29 south of Kelseyville.
Estimated 14 inches of snow.
Social media report of 8 inches of snow at an elevation of 2450 feet.
Social media report of 21 inches of snow at an elevation of 2300 feet.
Social media report of 10 inches of snow at an elevation of 2800 feet.
Social media report of at least 20 inches of snow at an elevation of 2400 feet.
Six inches of snow at an elevation of 1300 feet.
Public report of 24 inches of snow at an elevation of 2300 feet.
Public report of 17 inches of snow at an elevation of 2100 feet.
Snowfall total of 10 inches at an elevation of 2078 feet.
Snowfall total of 2 inches in Potter Valley. Elevation estimated to be 948 feet.
Snowfall total of 17 inches at an elevation of 2821 feet.
Snowfall total of 13 inches at an elevation of 2000 feet.
Snowfall total of 14 inches in the Brooktrails subdivision of Willits.
Snowfall total of 16 inches at an elevation of approximately 4000 feet.
Snowfall total of 13 inches at an elevation of 2970 feet.
Snowfall total of 11 inches at an elevation of 2850 feet.
Snowfall total of 11 inches at an elevation of 3000 feet.
Estimated 27 inches of snow at an elevation of 2500 feet.
Estimated 4 inches of snow at an elevation of 1808 feet.
Estimated 8 inches of snow at Collier Tunnel on Highway 199.
Estimated 24 inches of snow at an elevation of 2400 feet.
Estimated 4.5 inches of snow at an elevation of 2800 feet.
Thirty inches of snow at an elevation of 2650 feet.
Seven inches of snow at an elevation of 1500 feet. Numerous trees reported down. Highway closed.
Highway 175 closed east of Hopland due to 2 inches of snow.
Social media report of 8 inches of snow at an elevation of 2188 feet.
Snowfall total of 2 inches at an elevation of 1276 feet.
Snowfall total of 10 inches at an elevation of 2800 feet.
Social media report of 4 inches of snow at an elevation of 2000 feet.
Measured gust of 75 mph at the PGE station on Upper Bear River Road. Elevation of the observation was 1696 feet.
Measured gust of 62 mph at CECC1. Ob site is at sea level.
Snowfall total of 2 inches at an elevation of 1450 feet.
Two inches of snow at an elevation of 3223 feet.
Measured gust of 72 mph at the Kneeland RAWS. Elevation was 2737 feet.
Measured gust of 62 mph at sea level.
Six inches of snow over a period of 2.5 hours. Elevation was 2323 feet.
Multiple trees down on Highway 96 north of Willow Creek. Full closure of road overnight. Nearest wind observation gusted to 37 mph near the time of the report.
Two inches of snow at an elevation of 1600 feet.
One inch of snow at an elevation of 1500 feet.
Two inches of snow at an elevation of 1200 feet.
Six inches of snow at an elevation near 4900 feet.
Six inches of snow at an elevation of 2300 feet.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, January 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 933243, 933257, 933272, 933624, 933244, 933264, 933620, 933621, 933622, 933623, 933625, 933626, 933627, 933631, 933647, 933249, 933251, 933252, 933253, 933263, 933270, 933271, 933613, 933714, 933254, 933259, 933262, 933273, 933312, 933313, 933314, 933315, 933608, 933609, 933610, 933611, 933615, 933616, 933619, 933628, and more.